Population size, breeding success and distribution of Bewick's Swans Cygnus columbianus bewickii wintering in Europe in 1986-87
Article Sidebar
Main Article Content
Abstract
In 1986-7 two international censuses of the European wintering population of Bewick's Swans were organised, in January and March. The total of the January census (14,600-16,000) was influenced by adverse weather, but came close to the totals reached in recent years. The census in March revealed that only a few birds are east of East Germany in the early spring migration period. Breeding success in 1986 was low. There is a large and so far unsolved discrepancy between the population size estimated in winter from censuses in Western Europe (16 to 17 thousand) and the most recent estimate of numbers at the breeding grounds in northern Russia (30 to 36 thousand).
Article Details
Articles in Wildfowl volumes 1-74 and in Wildfowl Special Issues 1-7 are not licensed under Creative Commons. In these volumes, all rights are reserved to the authors of the articles respectively.
The Wildfowl & Wetlands Trust (which published the journal from 1948–2020 inclusive) retains a royalty-free license in perpetuity to access and use pre-2021 issues for the purposes of research, which may involve sharing with research partners from time to time.
The copyright for this paper belongs to the Author(s). Papers published in Wildfowl 75 (in 2025) and subsequent issues are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
In the articles published in these volumes, all rights are reserved to the authors of the articles respectively. This implies that readers can download, read, and link to the articles, but they cannot republish the articles. Authors can upload their articles into an institutional repository.